dioptre
Optical power unit
A dioptre is a unit of measurement for the optical power of a lens or curved mirror, equal to the reciprocal of the focal length in meters.
A lens with a focal length of half a meter has a power of two dioptres.
Eyeglass prescriptions are expressed in dioptres: She needs a prescription of minus three dioptres.
Also spelled diopter.
Medical dispensing authorization
- myopiaBlurry distance vision
- hyperopiaDifficulty seeing nearby objects
- astigmatismIrregular corneal curvature disorder
- presbyopiaAge-related near vision loss
eyeglasses · spectacles · contact lenses · bifocals · trifocals · progressive · corrective lenses · reading glasses
Vision care professional
- ophthalmologistEye disease physician
- optometryEye and lens healthcare
- ophthalmologyMedical specialty for eyes
- eye examAssessment of sight
refraction · retinoscopy · vision screening · glasses prescription · contact lens fitting
Lens-to-convergence-point distance
- curvatureDeviation from flatness
- vergenceOpposite eye movements together
- sphericalGlobe-like in form
- cylinderCircular-based solid form
axis · prism · unit · power · magnification · accommodation · convergence · divergence
Wave bending between media
- convexCurved outward externally
- concaveCurving inward, not outward
- convergingMoving toward sameness
- divergingSeparating from a common point
prescription
Medical dispensing authorization
- myopiaBlurry distance vision
- hyperopiaDifficulty seeing nearby objects
- astigmatismIrregular corneal curvature disorder
presbyopia · eyeglasses · spectacles · contact lenses · bifocals · trifocals · progressive · corrective lenses · reading glasses · distance vision
optometrist
Vision care professional
- ophthalmologistEye disease physician
- optometryEye and lens healthcare
- ophthalmologyMedical specialty for eyes
eye exam · refraction · retinoscopy · vision screening · glasses prescription · contact lens fitting
focal length
Lens-to-convergence-point distance
cylinder · axis · prism · unit · power · magnification · accommodation · convergence · divergence
refraction
Wave bending between media
- convexCurved outward externally
- concaveCurving inward, not outward
- convergingMoving toward sameness
diverging · lens · light bending · focal point · ray tracing
ophthalmoscope
Device for viewing retinas
- topographerOne who charts terrain